Apolipoprotein A-I Binding Protein, or ApoA-I binding protein (AMP), also called also called NAXE, NAD(P)HX epimerase, is a secreted protein discovered in a screen of proteins that physically associate with apoA-I (8). The human AIBP gene (APOA1BP) is located at 1q22. AIBP is a secreted protein. It has a presumed N-terminal signal peptide, which likely is cleaved off the protein during protein secretion from the cell.
Persistent pain states (greater than 3 months), arising from inflammatory disease (e.g., arthritis, 41 million people in the US; cancer, 8.5 million; and back pain, 6 million1) have extraordinary negative impact on quality of life. While opiates, NSAIDs, and anticonvulsants can relieve pain for short intervals, they are less effective for chronic therapy, particularly when components of the pain state involve persistent inflammation and/or injury to the peripheral nerve2-4. Aside from efficacy, many of the potent agents are beset with limiting side effects and issues related to dependence and addiction5. This relative lack of long-term efficacy of even approved agents is evident from clinical trial results, which often indicate that most subjects complete even successful trials with pain that is sufficiently severe as to permit reentry into the same trial6.
The pain states arising from local tissue injury or inflammation typically show a time course that parallels the onset and resolution of the injury state7, whereas nerve injury leads to a persistent pain state. However, as reported in humans, there is a growing appreciation that the pain originating from prolonged inflammation may persist even when the inflammatory state resolves, i.e. neutrophils, macrophages or cytokines are no longer detected. Thus, following surgeries such as herniorrhaphies, arthroscopies and thoracotomies, up to 30% of the populations may show pain that last greater than 3 months8,9. In the classic clinical example of persistent inflammation, rheumatoid arthritis is characterized by joint inflammation, joint remodeling, and pain. While the association of pain with inflammation is not unexpected, patients continue to report moderate to severe pain despite remission or showing minimal inflammatory signs10,11, suggesting the development of a chronic pain state.